Behaviour of Fish in Bottom-Trawling Gear to Assess the Effectiveness of Cetacean Excluder Devices and Codend Selectivity Modifications

The selective retention of fish is a consequence of size and species-dependent fish behaviour during the trawling process. The observation of fish reactions to trawl gear is critical to understanding the behavioural mechanisms responsible for trawl selectivity and to develop future trawl gear for research. In demersal trawling, there is a need to develop more species-selective trawls to minimize discarding and bycatch in multispecies fisheries. This requires observational tools that can operate at depths and light levels encountered by the commercial fleets and with the ability to quantify the herding and capture efficiency by species and age groups of such gears. A range of optical and acoustic observation techniques has been developed over the past few decades to assist in these goals. Work with underwater cameras in fishing gear varies from the simple observation of the presence of certain species during capture to the study of the complex interactions of fishing gear and species during the trawling process. Previous work seems to show that there are different response patterns in the general behaviour of some fish species when entering a trawl. One of these behaviours is that the vertical preference in the trawl cavity differs between species. Several authors have complemented behavioural studies carried out at sea with experimental studies to further explore the interaction between fish and fishing gear. Some authors indicate that the vertical preferences of some fish species change as they move through the net towards the codend. This implies that behavioural selection can potentially change along the horizontal axis of the fishing net. A description of the bycatch (cetaceans, sharks, and skates) and fish behaviour within bottom trawling gear was given through the use of underwater cameras. The objective was to determine the most suitable fishing gear configurations to prevent the escape of the fishing catch during fishing trials carried out to test the operation of dolphin-exclusion devices and selective codends. The behaviours recorded by the cameras were classified into seven types of behaviour: orientation, reaction, resistance, re-entry, final entry, escape attempts, and panic reaction

REM technology to help fulfill the landing obligation in European fisheries towards more sustainable fishing

Póster.-- Iberian Symposium on Modeling and Assessment of Fishery Resources, 19-22 October, Vigo, SpainThe main control measures used in EU fisheries are the use of logbooks, monitoring of vessel geographic positions and the inspections of the vessels at sea (patrol vessel surveillance) and at the ports (inspection of the landings). Many studies indicate that this traditional control measures are not effective within the current Landing Obligation rules. The Remote Electronic Monitoring (REM) is currently considered as one of the best future alternatives for the control of fishing activity. In fact, many fleets have already incorporated this technology into their activity to respond to the requirements of regional fishing organizations and control authorities in many countries of the world. The aim of this work was to test the implementation of innovative technologies based on artificial vision devices for catch composition determination and data management technologies installed on board. A study case including onboard observer trials and an automatic device was carried out to characterize discards and record unwanted species occurrence in commercial vessels. The “iObserver system” was implemented to improve the quality and availability of data and consequently to deepen knowledge on the status of the fisheries resources. This technology is aimed to be able to identify and quantify the catch (targeted and discarded) without interfering with the activity of fishermen. Once the data (species and biomass estimation) is acquired by iObserver, information is pre-processed and transmitted to land (to management servers). This system will allow real-time decision making for the fishing activity in order to eventually perform a more selective fishing. Automatic estimates of discards by species allow to take real-time decisions, avoid areas/times with high discards rates and potentially to comply with landing obligationN

Characterisation of common skate species Dipturus spp. through molecular and morphological identification

Elasmobranchs are marine vertebrates with a global decline in catches due to overfishing (2). Skates and rays have particular biological characteristics including large sizes, slow growth, late reproduction and low fecundity, which increase vulnerability to fisheries (4). They present a high morphological variability during their growth, which makes a correct identification difficult; there is scientific evidence of misidentifications and mixtures of species, which prevents a proper fisheries management. In fisheries management it is very useful to combine morphological and molecular techniques for the unequivocal identification of species. The EU has established a landing ban on the common skate, Dipturus batis, which inhabits the Northeast Atlantic, and it is currently listed as "critically endangered" by the IUCN (1) due to overfishing (6). In addition, there is currently a great controversy surrounding the taxonomic confusion of this skate, since this species was considered in the literature as a single species, being in fact a complex of species formed by the provisionally named Dipturus batis and Dipturus intermedia (3, 5, 6). The aim of this study is to combine morphometric and molecular analyses for the correct identification. For the analyses, samples of Dipturus batis, Dipturus oxyrinchus and Dipturus nidarosiensis were taken. Type entire specimens were storage for morphometric analysis, and muscle samples preserved in absolute alcohol for genetic analysis. Twenty-nine morphometric measurements were taken from each type specimen and DNA extraction on muscle and amplification of two mitochondrial, genes were performed, a Cytochrome Oxidase I (COI) fragment (aprox. 600pb) and a 16S fragment (aprox. 500pb). Identification was made through the Basic Local Alignment Search Tool of GenBank. According to the preliminary results obtained from the analysis of the sequences, this would correspond mainly to D. batis

Frequent and simultaneous epigenetic inactivation of TP53 pathway genes in acute lymphoblastic leukemia

Aberrant DNA methylation is one of the most frequent alterations in patients with Acute Lymphoblastic Leukemia (ALL). Using methylation bead arrays we analyzed the methylation status of 807 genes implicated in cancer in a group of ALL samples at diagnosis (n = 48). We found that 154 genes were methylated in more than 10% of ALL samples. Interestingly, the expression of 13 genes implicated in the TP53 pathway was downregulated by hypermethylation. Direct or indirect activation of TP53 pathway with 5-aza-29-deoxycitidine, Curcumin or Nutlin-3 induced an increase in apoptosis of ALL cells. The results obtained with the initial group of 48 patients was validated retrospectively in a second cohort of 200 newly diagnosed ALL patients. Methylation of at least 1 of the 13 genes implicated in the TP53 pathway was observed in 78% of the patients, which significantly correlated with a higher relapse (p = 0.001) and mortality (p,0.001) rate being an independent prognostic factor for disease-free survival (DFS) (p = 0.006) and overall survival (OS) (p = 0.005) in the multivariate analysis. All these findings indicate that TP53 pathway is altered by epigenetic mechanisms in the majority of ALL patients and correlates with prognosis. Treatments with compounds that may reverse the epigenetic abnormalities or activate directly the p53 pathway represent a new therapeutic alternative for patients with ALL

Preclinical activity of LBH589 alone or in combination with chemotherapy in a xenogeneic mouse model of human acute lymphoblastic leukemia.

Histone deacetylases (HDACs) have been identified as therapeutic targets due to their regulatory function in chromatin structure and organization. Here, we analyzed the therapeutic effect of LBH589, a class I-II HDAC inhibitor, in acute lymphoblastic leukemia (ALL). In vitro, LBH589 induced dose-dependent antiproliferative and apoptotic effects, which were associated with increased H3 and H4 histone acetylation. Intravenous administration of LBH589 in immunodeficient BALB/c-RAG2(-/-)γc(-/-) mice in which human-derived T and B-ALL cell lines were injected induced a significant reduction in tumor growth. Using primary ALL cells, a xenograft model of human leukemia in BALB/c-RAG2(-/-)γc(-/-) mice was established, allowing continuous passages of transplanted cells to several mouse generations. Treatment of mice engrafted with T or B-ALL cells with LBH589 induced an in vivo increase in the acetylation of H3 and H4, which was accompanied with prolonged survival of LBH589-treated mice in comparison with those receiving vincristine and dexamethasone. Notably, the therapeutic efficacy of LBH589 was significantly enhanced in combination with vincristine and dexamethasone. Our results show the therapeutic activity of LBH589 in combination with standard chemotherapy in pre-clinical models of ALL and suggest that this combination may be of clinical value in the treatment of patients with ALL